Cleaning device for dust separating apparatus



Jan. 10, 1967 N. DOCK 3,296,778

CLEANING DEVICE FOR DUST SEPARATING APPARATUS Filed March 25, 1965 c W 7 j c 2 LL r" /7 c" 6 INVENTOR NI LS DOCK L WW AT'TYS.

United States Patent Ofitice 3,296,778 Patented Jan. 10, 1967 3,296,778 CLEANING DEVICE FOR DUST SEPARATING APPARATUS Nils Dock, Saltsjo-Dnvnas, Sweden, assignor to Aktieholaget Svenska Flaktfahriken, Stockholm, Sweden Filed Mar. 23, 1965, Ser. No. 442,111 Claims priority, application Sweden, Mar. 31, 1964, 3,897/64 4 Claims. (Cl. 55-296) The present invention relates to a cleaning device in dust separating apparatus for flue gases and other dust laden media consisting of a number of small cyclones located in a gas channel or a channel-like housing. As shown in US. Patent Number 2,848,061, the cyclones are arranged superposed in rows side by side. The clean gas outlets of said cyclones are mounted in apertures in a partition arranged across the channel, and the dust outlets turning to the raw gas inlet side are provided with axially displaceable cleaning devices and are connected to an outlet duct for each vertical cyclone row, which dust is composed of a number of duct segments joined with an associated small cyclone.

In hitherto known dust separating apparatus of the above-mentioned type, as shown in US. Patent Number 2,848,066, a cleaning device, a so called cleaning spiral, is commonly used to avoid clogging in the dust outlets and the clean gas ducts of the cyclones of the apparatus. On the other hand, there is no cleaning device in the outlet ducts, which connect the dust outlets of the cyclones disposed above each other. It has, however, proved that in many cases heavily adherent dust has created such solid deposits in the ducts that they have been fully blocked. This clogging starts at the top of the duct, where the transport velocity is very low. This velocity, however, increases successively downwards in proportion to the quantity of secondary gas supplied to the outlet duct through the respective dust outlets.

The invention, which has as its object to eliminate these dust cloggings easily and suitably, is characterized in that the vertical outlet ducts are provided with cleaning devices which are axially displaceable in said duct and consist of scrapers, the number of which correspond to the number of cyclones of each vertical row. The scrapers are fastened to a vertical rod and are made as pairs of wire bows fastened to the rod at the upper and lower ends. Each bow has an upper horizontal part with an arched shape corresponding to the curvature of the outlet duct and merging into a vertical part, the lower end of which is curved towards the rod with an arched shape similarly corresponding to the curvature of the duct. The vertical extension of the bows and the location and displacement (stroke) of the rod in the outlet duct further is chosen so that the scrapers when cleaning do not pass beyond the adjacent duct joints.

Owing to the heavy adherence, in actual cases, of the dust deposited in the outlet ducts, the use of scraping cleaning devices according to the invention has proved to be technically advantageous, since no deterioration of the cleaning efiiciency of the cyclones occurs during cleaning of the outlet ducts.

The invention will now be more fully described with reference to the accompanying drawing showing an exemplifying embodiment of the invention, wherein FIG. 1 is a fragmentary side elevation partly in section of apparatus embodying a cleaning device according to the present invention; and

FIG. 2 is a fragmentary horizontal sectional view taken on the line IIII of FIG. 1.

With reference to the drawing, the dust separating apparatus comprises a plurality of individual units arranged in side-by-side rows. Each unit consists of a Wall portion 11 having an aperture therein in which is mounted a small cyclone 12 having dirty gas inlet 13, a clean gas outlet 14, and a dust outlet 15. A cleaning spiral 16 is mounted in the clean gas outlet 14 and projects into the dust outlet 15 to be periodically actuated to avoid clogging of the outlets. Each unit includes a discharge duct segment 17 connected to the dust outlet 15 through which the separated dust is discharged. As shown in FIG. 1, the units are mounted in superposed relation so that the wall portions 11 thereof form a continuous partition across a gas channel or channel-like housing and the duct segments are interconnected to form a continuous outlet duct.

In accordance with the invention, a cleaning device 1 is mounted in the outlet duct formed by the duct segments 17. As shown, the cleaning device 1 consists of a vertical rod 3 having scrapers 2 mounted thereon corresponding in number to the number of units in each vertical row. Each scraper 2 consists or a pair of wire bows fastened at their opposite ends to the rod 3. Each bow has an upper horizontal part 5 with an arched shape corresponding to the curvature of the duct segment 17. The part 5 merges into a vertical section 6, the lower end 7 of which is curved towards the rod 3 with an arched shape similarly corresponding to the curvature of the duct segment 17. The vertical extension of the bows and the location and stroke of the rod 3 is chosen so that the scrapers when cleaning, do not pass beyond the adjacent joints between the duct segments 17.

It is noted that the arcuate extent of the parts 5 and 7 of the scraper is such that the bows do not infringe upon the dust outlets 15 and therefore, do not detract from the cleaning efficiency of the cyclone during cleaning of the ducts.

While a particular embodiment of the present invention has been herein illustrated and described, it is not in tended to limit the invention to such disclosure, but changes and modifications may be made therein and thereto within the scope of the following claims.

I claim:

1. In apparatus for separating dust consisting of a partition arranged across a gas channel or a channel-like housing, a number of small cyclones having clean gas outlets mounted in apertures in said partition in superposed relation in a vertical row, and dust outlets connected to an outlet duct for said vertical row, the improvement wherein the vertical outlet duct is provided with a cleaning device axially displaceable in said duct and consisting of a vertical rod and scrapers, said scrapers corresponding in number to the cyclones of said vertical row, each scraper comprising a pair of wire bows fastened at their upper and lower ends to said rod and having an upper horizontal part with an arched shape corresponding to the curvature of the outlet duct, a vertical part, and a lower end curved towards the rod and having an arched shape similarly corresponding to the curvature of the duct.

2. In apparatus according to claim 1 wherein said vertical duct comprises a plurality of duct segments corresponding in number to the cyclones of said vertical row, and interconnected by joints, the improvement wherein the vertical extension of the bows and the location and stroke of the rod in the duct is such that the scrapers when cleaning, do not pass beyond the adjacent duct joints.

3. Apparatus according to claim 1 wherein said clean gas outlets and duct outlets are provided with axially displaceable cleaning devices.

4. Apparatus according to claim 1 wherein the circumferential extent of said arched upper and lower ends of the 3 bows is such that they do not infringe upon the connection of said dust outlets to said duct, avoiding deterioration of the cleaning efliciency of the cyclones during the cleaning operation.

References Cited by the Examiner UNITED STATES PATENTS 745,642 12/1903 Miller 15-104.16

795,227 7/ 1905 Krentler 15242 2,331,720 10/1943 Osgood 55430X FOREIGN PATENTS 5/ 1930 Great Britain. 4/1961 Great Britain. 4/ 1961 Great Britain.

10 HARRY B. THORNTON, Primary Examiner.

D. TALBERT, Assistant Examiner. I 

1. IN APPARATUS FOR SEPARATING DUST CONSISTING OF A PARTITION ARRANGED ACROSS A GAS CHANNEL OR A CHANNEL-LIKE HOUSING, A NUMBER OF SMALL CYCLONES HAVING CLEAN GAS OUTLETS MOUNTED IN APERTURES IN SAID PARTITION IN SUPERPOSED RELATION IN A VERTICAL ROW, AND DUST OUTLETS CONNECTED TO AN OUTLET DUCT FOR SAID VERTICAL ROW, THE IMPROVEMENT WHEREIN THE VERTICAL OUTLET DUCT IS PROVIDED WITH A CLEANING DEVICE AXIALLY DISPLACEABLE IN SAID DUCT AND CONSISTING OF A VERTICAL ROD AND SCRAPERS, SAID SCRAPERS CORRESPONDING IN NUMBER TO THE CYCLONES OF SAID VERTICAL ROW, EACH SCRAPER COMPRISING A PAIR OF WIRE BOWS FASTENED AT THEIR UPPER AND LOWER ENDS TO SAID ROD AND HAVING AN UPPER HORIZONTAL PART WITH AN ARCHED SHAPE CORRESPONDING TO THE CURVATURE OF THE OUTLET DUCT, A VERTICAL PART, AND A LOWER END CURVED TOWARDS THE ROD AND HAVING AN ARCHED SHAPE SIMILARLY CORRESPONDING TO THE CURVATURE OF THE DUCT. 